Predicting the Viscosity of Asymmetric Hydrocarbon Mixtures with the Expanded Fluid Viscosity Correlation

Abstract

Mass-based mixing rules are proposed for the Expanded Fluid viscosity correlation that are suitable for asymmetric mixtures and replace the original volumetric mixing rules. The Expanded Fluid correlation provides viscosity values as a function of fluid density and characterizes each pure compound with three fluid-specific parameters: c2, ρso and c3, when using experimental densities and two parameters, c2, ρso, when using a cubic equation of state. The proposed set of mixing rules predicts the viscosity of over 90 binary mixtures with overall average absolute relative deviations (AARD) of 2.9% and 7.8% using measured densities and densities estimated from an equation of state, respectively. To improve the predictions in equation of state applications, a binary interaction parameter is introduced to the mixing rules, compensating for inaccuracies associated with density predictions from simple cubic equations of state. Using fitted interaction parameters, the overall AARD is 3.6%. The binary interaction p...